WEDNESDAY, June 2 (HealthDay News) -- A new study may reassure parents about what they believe -- or hope -- is true: Teenagers tend to mature as they get older.

The longitudinal study found that as teens become young adults, many -- but not all -- will find that their tendency toward impulsive behaviors decreases, along with the amount of alcohol they consume.

The finding is the product of a study published in the August issue of Alcoholism: Clinical & Experimental Research, based on research co-authored by Andrew K. Littlefield, a doctoral student in clinical psychology in attendance at the University of Missouri.

"Traits related to impulsivity tend to normally decrease from late adolescence into early adulthood, approximately from ages 18 to 35," Littlefield said in a news release.

The authors analyzed data concerning 489 college students at risk for alcohol abuse because of a family history of alcoholism.

Over the course of 15 years, starting in their freshman year at a public university, the students were assessed for developmental changes and drinking patterns.

"Of most importance, our findings suggest that individuals that made the steepest decreases in impulsivity also made the sharpest decreases in alcohol use and alcohol-related problems from ages 18 to 25," said Littlefield.

"Many researchers and clinicians think of personality as an incredibly stable construct that does not change across time," he added. "However, these findings provide clear evidence that at least some individuals undergo significant changes in impulsivity across time."

"Future studies could examine why some individuals make significant changes in impulsivity across time whereas other individuals' level of impulsivity remains relatively stable," Littlefield added. Such information, he said, could help with the development of new treatment approaches.